Network Fundamentals

Agenda

• Basic Terms
• OSI and TCP/IP Model
• Protocols
• Advanced Topics

Basic Terms

Client

MAC Address

• 12 Character Number assigned to each Client
• Used to address local Clients over Wire or Wireless
• Can usually be changed manually

IP Address

• Two Version 4 and 6
• 32 or 128 Bit
• Used to address Clients
• Can be changed within the local Network
• Mostly fixed for public IP address

Switch

Router

OSI and TCP/IP Model

OSI Model

TCP/IP Model

OSI vs TCP/IP Model

Protocols

Address Resolution Protocol (ARP)

• Maps MAC to IP Address
• Local Cache of Mapping
• Request for missing Items
• Data Link or Network Access Layer

Transmission Control Protocol (TCP)

• Protocol for delivering Messages
• Reliable, Ordered and Error Checked
• Transport Layer

User Data Protocol (UDP)

• Protocol for delivering Messages
• Shoot and Forget, Fast
• Transport Layer

File Transfer Protocol (FTP)

• Used to transfer Files
• Application Layer
• Port 21

Secure Shell (SSH)

• Securely access Computer over insecure Network
• Application Layer
• Port 22

Dynamic Host Configuration Protocol (DHCP)

• Automate Network Configuration of Service
• Network and Data Link or Network and Network Access Layer
• Port 67

Domain Name System (DNS)

• Map IP Address to Hostname
• Application Layer
• Port 53

Hypertext Transfer Protocol (HTTP)

• Used to transfer and interact with Media
• Application Layer
• Port 80

Routers and Firewalls

Routing

• How to reach other Network

Rules

• IPs
• Ports
• Protocol
• Dangerous Traffic

VPN

• Secure Connection over insecure Network
• Encryption
• Hide private Information
• Access internal Resources